CLN2 disease is caused by TPP1 deficiency, leading to progressive neurodegeneration, profound neuroinflammation, and seizures. Screening FDA approved drugs in a zebrafish model of TPP1 deficiency recently identified the neurosteroid pregnenolone as a potential therapeutic intervention. In this study, we assessed the effect of dietary pregnenolone supplementation in the Tpp1R207X/R207X mouse model of CLN2 disease. Pregnenolone was administered orally at an estimated therapeutically relevant dose of 1200 mg/kg/day, delivered in a gelatin-based cube, with cubes that contained no drug serving as a placebo control. This treatment was started post-weaning, with mice of both genotypes readily consuming these cubes. Brain tissue was collected from mice at normal disease endstage (3.5 months), with additional mice serving as a survival cohort. Brains were analyzed using immunohistochemistry for storage material burden (SCMAS), microglial activation (CD68), and astrocytosis (GFAP) in the primary somatosensory cortex (S1BF) and associated thalamic relay nuclei (VPL/VPM). Compared to wild-type controls, placebo treated CLN2 mice showed pronounced disease-associated pathology across all markers. Pregnenolone-treated Tpp1R207X/R207X mice displayed significant reductions in CD68 and GFAP immunoreactivity, indicating attenuation of microglial and astrocytic activation. However, SCMAS levels were unaffected, indicating that pregnenolone had no impact on storage material accumulation. We also saw no extension of lifespan in pregnenolone treated Tpp1R207X/R207X mice. Our findings indicate that although pregnenolone does not clear lysosomal storage, it partially modulates neuroimmune responses in CLN2 mice. Further work will be required to determine if there was any impact on the seizure phenotype of these mice. Nevertheless, this effect on glial activation may warrant further investigation of pregnenolone in combination with disease-modifying therapies such as enzyme replacement or gene therapy.